1. Field of the Invention
The field of the invention relates to wall structures, and particularly to precast concrete wall structures for use as sound barriers, containment walls and like purposes.
2. Description of the Prior Art
Precast concrete walls are used for a variety of purposes, including noise abatement in areas where there exists high volume traffic adjacent to residential or commercial areas and including containment purposes. Concrete walls have been found to be desirable for noise abatement purposes due to the insulating characteristics, impact resistance and weathering characteristics of concrete. Concrete walls provide many of the advantages of earthen berms, but require substantially less space. Concrete walls are additionally desirable, for like reasons, for containment walls.
In some installations, such as applications involving concrete building walls, concrete wall modules are poured on site, tilted to an erect position and joined with other wall sections. It is often more economical, however, to cast wall modules offsite and transport the wall modules to the construction site.
Appropriate joining and support of concrete wall modules to withstand wind shear and impact stresses is necessary. It is further necessary to have the ability to adjust wall levels to account for varying terrain elevation.
Joining and support of concrete wall modules, as commercially practiced, typically involves casting columns in place and inserting precast wall modules between the columns. The columns extend into the earth to provide anchoring for the walls. The columns are typically provided with vertical channels, the vertical channels receiving ends of the wall panels. Precast wall sections are typically lifted with a crane to a position above the columns and lowered into the channels provided in the columns. As such walls are often constructed along highways near electrical power and telephone lines, it is often necessary that such utility lines be disconnected to accommodate construction of the walls. Wall sections may be relatively high, typically including height ranges of twelve feet to twenty feet. As such sections are raised above columns of like height, it is necessary to provide a crane having relatively high load capacity and boom length.
Smith, et al., U.S. Pat. No. 4,402,384 discloses a sound barrier system comprising a vertical wall composed of successive individual wall sections arranged with intermediate wall sections disposed at intersecting angles. Anchors are provided at each vertical joint, the anchors comprising screw-type augers in a preferred embodiment.
In recognition of limitations inherent in conventional concrete wall construction methods various wall systems providing noise abatement have been developed.
Gavel U.S. Pat. No. 4,146,113 discloses a noise protection screen comprising a plurality of hollow, interconnected members, the members inclined at an angle to the horizontal.
Reusser U.S. Pat. No. 4,306,631 discloses a noise barrier including spans extending between posts, the spans having interlocking elements.
Lerner, et al. U.S. Pat. No. 4,278,146 discloses a sound barrier comprising a series of sections separated by V-shaped ribs, with acoustical material contained in the cavities defined by the ribs.
It is an object of the present invention to provide a wall structure wherein the wall section and a support column are precast as an integral unit.
It is a further object of this invention to provide a wall structure wherein the wall sections may be installed without the necessity of lifting wall sections above columns.
It is a further object of this invention to provide a wall structure characterized by relatively quick and economical construction.